Lift truck



Dec. 10, 1940. w. STUEBING, JR 2,224,

- LIFT TRUCK Filed Feb. 3, 1940 2 Sheets-Sheet 2 INVENTOR WilliamStue-binj, ]3'.

KTTORNEYS Patented Dec. 10 1940 UNITED STATES 2,224,166 LIFT TRUCKWilliam Stuebing, Jr., Cincinnati, Ohio, assignor to Lift TrucksIncorporated,

a corporation of Ohio Cincinnati, Ohio,

Application February 3, 1940, Serial no. 317,069

5 Claims.

This invention relates to lift trucks and more particularly tohand-operated mechanical lift trucks which are operated by a releasabledirect mechanical connection between the steering handle and the liftingframe, and where the lifting operation is performed by a single downwardmovement of the steering handle.

An object of this invention is'to provide a manually operated mechanismfonlifting and conveying articles which ordinarily are upon movableplatforms. A further object is to provide amechs anism of the abovecharacter which'ls sturdy in construction and efficient in operation andwhich, at the same time, is light in weight and economical tomanufacture. A still further object is to provide a mechanism of theabove character which may be used in a thoroughly practical anddependable manner to manually lift a large article or a quantity ofsmall articles by a single lifting operation and then, without furtherdelay, manually convey the lifted article to another location. Otherobjects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combination of elements, and arrangements of parts as will beexemplified in the structure to be hereinafter described and the scopeof the application of which will be indicated in the following claims.

In the drawings in which one embodiment of the invention is disclosed:

Figure l is a plan view with the steering handle of the truck in sectionalong the line l-l of Figure 2;

Figure 2 is a side view of the truck shown in Figure 1 with the steeringhandle broken away;

Figure 3 is a front view with the central portion of the steering handlebroken away;

Figure 4 is a sectional view on the line 44 of Figure 1. but showing thelifting frame raised and the other elements in the positions which theyoccupy at the end of the lifting stroke of the steering handle;

Figure 5 is a view similar to Figure 4 with the lifting frame elevatedbut showing the linkage mechanism after it has been released from thesteering handle;

Figure 6 is a perspective viewof the lifting hook which cooperates withthe end of the steering handle to provide the mechanical connectionbetween the handle and the lifting linkage mechanism; and

Figure '7 is a plan view of the idler link which connects the liftingframe with the lifting linkage mechanism.

In the illustrative embodiment of this invention,

the lift truck is completely manual. A lower frame is provided withwheels, and a lifting frame is mounted upon this lower frame to movevertically. Thus, the frames of the truck are pushed under the loadedplatform and the lifting frame is then elevated with the result that theload is supported by the lift truck. The lift truck is then moved to thenew location where the lifting frame is lowered releasing the load.

Referring particularly to Figure 2 of the drawings, a lower frame 2 isprovided at the left with a pair of rear wheels 4 mounted upon an axleE, and at the right with apair of front wheels 8 (see also Figure 3).Front wheels 8 are mounted upon the ends of an axle Ill which in turn iscarried by a fork I2 rigidly secured to the lower end of a king bolt M.King bolt l4 extends through a cross-head I8 which forms the forward endof the lower frame 2. As shown best in Figures 1 and 2, the lower frameis reenforced at the right I cross-beam 28, At the front, each end ofside member 24 is attached to lower frame 2 by a link 30 pivoted uponsuitable studs, and at the rear,.

lower frame 2 is provided with a cross bar 32, and lifting frame 22 isprovided'with a similar cross bar 34. Pivotally connecting these twocross bars are two links 36, Links 36 and 30 are of the same length,and, thus, the two frames remain parallel as the lifting frame swingsbetween its lower position (Figure 2) and its elevated position (Figures4 and 5) Lifting frame 22 is raised to the position shown in Figures 4and 5 by a linkage mechanism at the front of the truck, which isoperated by the steering handle 40. Rigidly mounted upon the top of wingbolt l4 and extending to the right (Figure 2) is a forked bracket 42which carries a pivot pin 44 extending between the two arms of thebracket (see also Figure 3). Pivot pin 44 carries a steering-handlesleeve 46 having two ears at its lower end which are pierced by andpivot upon pivot pin 44, there being one ear adjacent each of the twoarms of bracket 42. The body portion of steeringhandle sleeve 46 ishollow and slidably receives the lower end of the steering-handle 40(see Figure 5). The rear central portion of the steeringhandle sleeve iscut away at 48, and mounted upon the opposite sides of steering-handleill at 48 (Eli are two blocks 50. Blocks 50 are shorter than the lengthof the cut-away portion 48 and thus, the steering handle is permitted alimited sliding movement with respect to the steering-handle sleeve 45;

Mounted upon the center of pivot pin 44 between the ears ofsteering-handle sleeve 45 is a segment-hook 52 which is shown best inFigure 6. Segment-hook 52 is provided with a disc segment 54 having aradial surface 55, and a hook portion 56. At the base of the hookportion is a bumper 58 which, as shown -in Figure 5, limitscounterclockwise movement of the segment-hook. In operation, hook 56 isengaged with the eye 60 of a lifting link 52, the lower portion of which(see Figure 1) is formed by a U-bolt 64 rigidly secured by nuts 65. Thelower end of U-bolt 54 is looped into one eye of an idler link 68 (shownin Figure 7), the other end of which is carried by a pivot pin 10rigidly mounted at the center of the cross-beam of lifting frame 22.

The lower end of steering handle 40 is provided with a latch portion 12which, as shown best in Figure 4, is adapted to engage with the segmentportion 54 of segment-hook 52. When thus engaged, the linkage mechanism,including segment-hook 52, lifting link 62 and idler link 58, is movedby the steering handle. If the steering handle is raised to the positionof Figure 2, the limited sliding movement between steering handle 49 andsteering-handle sleeve 45 permits the steering handle to move downwardlytoward pivot pin 44 so that the latch portion 12 moves along surface 55of segment 54. As the handle is then swung downwardly, the linkagemechanism moves to the position of Figure v4, and lifting frame 22 movesto its elevated position.

Referring to Figure 3, at the right of the steering handle and rockablymounted upon head I5 is a holding hook 15 which, as shown in Figure 1,

is provided with a foot treadle l5, and a hook portion 11 which, whenthe lifting frame is moved to the position of Figure 4, is adapted toengage a roller 15 carried by the lifting frame.

= when in this position, links and extend upwardly and slightly to therear so that they are substantially vertical but the lifting frame tendsto swing to the rear. Thus, by providing hook 15 which prevents rearwardmovement of the lifting frame, the lifting frame is rigidly held in itselevated position. In this embodiment, treadle 15 of hook 15 is urgedupwardly by a engages .sleeve so that latch portioh 12 is released fromengagement with surface of segment link 52. The extreme end ofsteering-handle 45 is provided with an arcuately extending end surfacewith the same curvature as the periphery of segthough the handle may beswung freely up and down. In this manner the steering handle isefflciently operated to elevate the lifting frame and then is used topull, push and steer the truck.

When it is desirable to lower the lifting frame, treadle 15 is depressedreleasing book 11 and the lifting frame tends to settle to the positionof Figures 1 and 2. However, in order to avoid rapid lowering of thelifting frame and its load, an automatic check 55 is provided (seeFigure l) Check 89 comprises an outer cylinder which is connected at itsleft end to the rear cross-beam 20 of lower frame 2 through a pivotconnection indicated at 82, and a check-piston connected to cross-beam29 of lifting frame 22 through a pieton rod and pivot connectionindicated at 54. The piston of check 55 may be moved to the rightwithout resistance, but rapid return movement to the left is resisted.Thus, the lifting frame is elevated and the piston is moved to the rightin the cylinder without resistance, but as the lifting frame starts todescend from its elevated position, the check becomes operative, and thelifting frame settles slowly to its lower position.

Referring to Figure 2, extending to the right from bracket 42 is an ear95 which carries a pivotally mounted pin 99, the upper end of whichextends through an ear 92 upon the top of steering-handle sleeve 45.Surrounding pin is a handle-balancing compression spring 94 which iscompressed between cars 92 and as the handle swings downwardly. Spring59 is adjusted to the conditions of usage and to the weight of handle 49so that the handle may be manipulated without difliculty. As shown inFigure 3, upon the opposite sides of steering-handle 45 are stops 95which cooperate with suitable stops 95 upon bracket 42 to limit thedownward swinging movement of handle 40.

When the lifting frame is in its lower position (Figures 1 and 2),segment 54 holds handle 4|! extended relative to sleeve 45 except whenthe handle is raised. However, when the handle is raised as in Figure 2,the handle automatically drops and latch 12 falls behind the left-handend of segment 52 so that latch 12 (see also Figure 4) moves alongsurface 55. Thus the handle is held from falling and may be used toelevate the lifting frame when desirable. Cross-brace 28 is providedwith a vertically extending load-bumper I09 which limits the movement ofthe truck under a load. The truck is therefore backed under the load asfar as it will go; the load is then raised by a single downward strokeof the steering handle. The handle is then pulled outwardly and thelinkage 52-55 drops to the position of Figure 5 so that the handle 40 isdisengaged from the lifting mechanism and held rigid with respect tosleeve 45.

As many possible embodiments may be made of the above invention and asmany changes might be made in the embodiment above set forth, it is tobe understood that all matter hereinbefore set forth. or shown in theaccompanying drawings. is to be interpreted as illustrative and not'in alimiting sense.

I claim:

1. In lift truck apparatus of the class described, the combination of: asteering handle pivotaily mounted to swing through a vertical arecomprising, a sleeve member pivotally mounted at one end, a main handlemember extending into said sleeve member toward the pivotal axis; meansto limit the relative sliding movement between said main handle memberand said sleeve member including a segment of a disc mounted with itsaxis substantially coincident with said pivotal axis,

said segment having a peripheral raceway along which an engaging surfaceof said main handle member rides, said segment being normally positionedto have said engaging surface ride along it during the normal swingingmovement of the handle from a substantially horizontal position to asubstantially vertical position, said main handle member being held atthe limit of its movement away from said pivotal axis by the engagementof said engaging surface with said peripheral raceway, said segmenthaving a radial surface which extends vertically when said segment is insaid normal position and said main handle member having integraltherewith a latch portion which drops behind said segment along saidradial surface when said main handle member reaches a vertical positionand is released to drop towards said pivotal axis due to said engagingsurface moving beyond said peripheral raceway--whereby said segment isswung downwardly by the subsequent downward swinging stroke of saidsteering handle.

2. In lift truck apparatus of the class described, the combination of:means forming a base including a pivot member mounted upon a wheeledsupport which is pivoted to obtain a steering action; a steering handlecomprising, a first member, and a second member having limitedlongitudinal movement with respect to said first member toward and awayfrom said pivot member; a segment-lever member rockably mounted to bemoved to and from a position where it is contacted by said second memberto hold said second memberin its extended position'away from said pivotmember; and means operative when said second member is moved toward saidpivot member and swung about its pivotal axis to effect elevation of aload.

3. In lift truck apparatus of the class described, the combination of:means forming a base in-' cluding a pivot member mounted upon a wheeledsupport which is pivoted to obtain a steering action: a steering handlecomprising, a first member, and a second member having limitedlongitudinal movement with respect to said first member toward and awayfrom said pivot member; a segment-lever member rockably mounted to bemoved to and from a position where it is contacted by said second memberto hold said second member in its extended position away from said pivotmember; means operative when said second member is movd toward saidpivot member and swung about its pivotal axis to effect elevation of aload; and a spring balancing means for said steering handle comprising,a spring guide rod pivoted about an axis spaced from the pivotal axis ofsaid steering handle, a compression spring surrounding said guide rod,and an ear carried by said steering handle and surrounding said guiderod to contact and compress said spring as said steering handle swingstoward its horizontal position.

4. In a manually operated lift truck, the combination of: a chassiscomprising a supporting frame having mounted thereon a set of wheels anda steering handle; a lifting frame mounted upon said chassis and adaptedto be'moved to and from a raised position where it engages and lifts aload; means to elevate said lifting frame comprising, an idler linkhaving two eyes one of which is attached to said lifting frame, anintermediate linkage having a lower U-shaped portion which is loopedinto the other of said eyes of said idler link and having an upper eye,and a segment-hook member having a hook portion extending through thelast named of said eyes and a segment portion extending in the plane ofsaid hook; a. pivot means forming a mounting for said steering handleand said segment-hook member, said steering handle comprising a sleevemember rockably mounted at one and upon said pivot means and a mainhandle member extending through said sleeve member and having limitedrelative movement with respect thereto, said main handle member beingmounted to swing in alignment with said segment and having an integrallatch portion which is adapted to engage said segment, said latchportion having an end surface which is adapted to ride along the arouateperiphery of said segment when said main handle is slid within saidsleeve member to its extreme outer position and said latch portion beingadapted to move along the radially extending side of said segment tothereby mechanically interengage said main handle member and saidsegment-hook member-whereby said main handle member may be interengagedwith said segment member to elevate said lifting frame by means of themechanical connection through said intermediate link and said idlerlink, and said main handle member may subsequently be movedlongitudinally in said sleeve member to cause said latch portion to rideon the peripheral surface of said segment and thereby prevent furtherlongitudinal movement of said main handle memher with respect to saidsleeve member; and releasable means to retain said lifting frame in itselevated position.

5. In a lift truck of the class which is manually pulled, pushed andsteered by means of a steering handle and which is backed to a positionbeneath a load and a lifting means is then manually operated to lift theload, whereupon the load is moved to a new location, the combination of:a chassis construction including a plurality of wheels; a load-engagingmeans including a plurality of collapsible linkages connected to saidchassis construction, said load-engaging means being adapted to movewhen the linkages are extended to engage and lift the load; holdingmeans to hold the load in elevated position comprising, a roller mountedupon said load-engaging means, a hook member rotatably mounted upon saidchassis construction to receive and hold said roller, and means torelease the engagement between said hook and said roller; and means tomove said load-engaging means into engagement with the load and elevatethe load comprising, a collapsible linkage unit including a plurality oflink members connected serially with a first end link member connectedto said load-engaging means and a second end link member rockablymounted upon a lifting pivot, a segment of a disc mounted with its axissubstantially coincident with the axis of said pivot and rigidly mountedwith respect to said second end link member to rock therewith about saidpivot, said collapsible linkage unit and said segment normally tendingto move due to gravity to one extreme position, and a main handle memberrockably mounted upon said pivot with its inner end adjacent saidsegment and mounted to slide longitudinally between an inner and anouter position toward and away from said pivot, said main handle memberhaving its inner end surface arcuately shaped to substantially thecurvature of the periphery of said segment and having a latch portionwhich is adapted to move along a radially extending surface of saidsegment when said main handle member is moved longitudinally to itsinner position, said main handle tending surface of said segment-wherebysaid handle may be swung downwardly about said pivot and saidload-engaging means is caused to engage and lift the load, and the loadis then releasably held by said holding means.

WILLIAM STUEBING, J R.

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